Transparent conductive laminate and touch panel using the same

ABSTRACT

This invention relates to a transparent conductive laminate and to a touch panel which uses the transparent conductive laminate and has excellent durability and excellent visibility. The transparent conductive laminate contains a transparent polymer substrate and a transparent conductive layer disposed on at least one of surfaces of the transparent polymer substrate, the transparent conductive layer has a surface containing micro bumps, wherein: (1) the transparent conductive laminate contains a cross-linked polymer layer (A) containing fine particles and a cross-linked polymer layer (B) between the transparent polymer substrate and the transparent conductive layer, said cross-linked polymer layer (A) is disposed between the transparent polymer substrate and said cross-linked polymer layer (B); (2) the cross-linked polymer layer (B) contacts the transparent conductive layer; and (3) the surface of said transparent conductive layer contains the bumps having an average height of 0.3 to 1 μm and a density in the range of 350 to 1,800 bumps/mm 2 . The transparent conductive laminate can be used as an electrode substrate to provide a touch panel which has excellent writing durability, does not generate interference fringes in the touch panel, and gives non-dim and easily readable letters on the display.

TECHNICAL FIELD

The present invention relates to a transparent conductive laminate andto a touch panel which uses the transparent conductive laminate and hasexcellent durability and excellent visibility.

BACKGROUND OF THE INVENTION

Recently, the wide employment of portable information-processingequipment on which a liquid crystal display for displaying informationand a touch panel (called a switch panel, a membrane switch or a tablet)for inputting information were loaded was started. Most of the touchpanels are resistant film type ones. Each of the resistant film typetouch panel is formed by facing two transparent electrode substrateshaving transparent conductive layers formed thereon, respectively, eachother at a distance of 10 to 100 μm. Both the transparent electrodesubstrates are brought into contact with each other only at a sitetouched by a finger, a pen, or the like, to act as a switch. Forexample, the selection of a menu on a display screen, the inputting of ahandwritten figure, handwritten letters, or so on, can be carried out.As the transparent electrode substrates, ones manufactured by disposingthe transparent conductive layers of a metal oxide such as indium tinoxide (ITO) or tin oxide containing antimony or the like on substratessuch as glass substrates or various kinds of transparent polymersubstrates are widely used.

In the touch panel, the transparent electrode substrate on the side tobe touched by the finger, the pen, or the like (movable electrodesubstrate), is preferable to be flexible from a point that the figure,letters, or the like, can easily be inputted. As the movable electrodesubstrate, an electrode substrate obtained by disposing a transparentconductive layer on a transparent polymer film substrate or atransparent polymer sheet substrate is usually used. There has been aproblem that, when a flexible transparent electrode substrate is used asa movable electrode substrate, the movable electrode substrate isloosened due to the changes of temperature and humidity, resulting inthe generation of interference fringes between the movable electrodesubstrate and the facing fixed electrode substrate to give an indistinctscreen. There has also been a problem that, when both the surface of amovable electrode substrate and the surface of a fixed electrodesubstrate are extremely flat, the electrode surface of the movableelectrode substrate and the electrode surface of the fixed electrodesubstrate are adhered to each other to cause the failure in theoperation of the touch panel.

In order to solve the problems, the present inventors proposed a methodfor making the surface of an electrode with micro bumps. In JP-A No.8-216327 (1996) (hereunder, JP-A means Japanese unexamined patentpublication) is described a touch panel that the generation ofinterference fringes was controlled by using a transparent conductivelaminate whose transparent conductive layer surface has a centralsurface average roughness (SRa) of 0.05 to 0.40 μm. In JP-A No. 10-24516(1998) is also described a transparent conductive laminate which usessilicone resin fine particles having an average particle diameter of 4.5μm and has an excellent slipping property and whose transparentconductive layer surface has a central surface average roughness (SRa)of 0.003 to 0.04 μm. Thereby, the problems of the generation ofinterference fringes and of the mutual adhesion of electrode surfaceswere solved, but writing durability was often insufficient. Namely, whena test for the writing durability was carried out, it was found that thepeeling of the transparent conductive layer was sometimes caused on theperipheries of the electrode surface bumps of a movable electrodesubstrate, resulting in the deterioration of the inputting performanceof the touch panel (for example, the generation of misprinting, theinsufficient accuracy of position detection) after the test of thewriting durability.

On the other hand, a transparent conductive laminate in which a coatinglayer containing fine particles was disposed between a transparentplastic film and a transparent conductive layer was proposed forimproving the writing durability (JP-A No. 10-249975 (1998)). Accordingto the description of the patent publication, the damages of thetransparent conductive layer were concentrated at extremely small areasaround the apexes of bumps, because the bumps were distributed on thesurface of the electrode at a proper density. Consequently, even whenthe transparent conductive layer was damaged, the total resistance ofthe transparent conductive layer was largely not changed, and theaccuracy of position detection was scarcely changed. Further, the goodaverage particle diameter of fine particles contained in the coatinglayer was in the range of from not less than the thickness of thecoating layer to three times or less than that of the coating layer, andthe good density of the particles was 10,000 to 500,000 particles/cm²(100 to 5,000 particles/mm²). However, the examinations of the presentinventors showed that the writing durability was always not improved,even when the density of the particles was set to the range.

Further, in JP-A No. 10-323931 (1998) is described a transparentconductive laminate in which a coating layer containing particles havingan average particle diameter of 1.0 to 4 μm at a number-average densityof 500 to 3,000 particles/mm² and a transparent conductive layer weresuccessively formed on a transparent plastic film to control thegeneration of interference fringes. However, the transparent conductivelayer surface of the laminate had a ten point height (Rz) of 0.3 to 1.0μm or larger, therefore comprised bumps of large dispersion of height,and the writing durability of the laminate was insufficient, when usedas a touch panel.

A main object of the present invention is to provide a transparentconductive laminate suitable for giving a touch panel having excellentwriting durability.

Another object of the present invention is to provide a touch panelwhich has good writing durability and excellent visibility.

DISCLOSURE OF THE INVENTION

The present inventors have paid attentions on the heights of bumps onthe surface of a transparent conductive layer and have researched tosolve the above-mentioned problems and obtain the touch panel whichscarcely generates interference fringes and has excellent visibilitygiving clear letters and excellent writing durability.

Consequently, the present inventors ascertained that the writingdurability did essentially not depend on the density of fine particlesand that the existence of bumps, which are higher than a certain height,especially caused a problem, when the surface of a transparentconductive layer used as the electrode of the touch panel had high bumpsand low bumps in a mixed state especially of large dispersion of height.

On the other hand, since adhesivity between the transparent conductivelayer and a substrate such as a polymer film was also important fordynamic mechanical durability called the writing durability, the presentinventors further repeatedly researched the point. It was consequentlyfound that a peeling was caused between the transparent conductive layerand a layer containing fine particles, when the layer containing fineparticles was disposed just under the transparent conductive layer in astate directly contacted with the transparent conductive layer. Theinventors also examined the point and in consequence found out that itwas important to control the height of bumps and the density of bumps inthe layer containing fine particles and that it was extremely effectiveto dispose a cross-linked polymer layer between the layer containingfine particles and the transparent conductive layer in a state contactedwith the transparent conductive layer.

The present invention was completed by repeating the researches on thebasis of the knowledge. Namely, the present invention relates to thetransparent conductive laminate which is obtained by controlling theheight of the bumps and the density of the bumps in the surface of thetransparent conductive layer, controlling the height of the bumps andthe density of the bumps in the surface of the layer containing fineparticles between the transparent conductive layer and the substrate,and disposing the cross-linked polymer layer in the state contactingwith the transparent conductive layer, and is especially useful for atouch panel.

Namely, the present invention is as follows.

A transparent conductive laminate comprising a transparent polymersubstrate and a transparent conductive layer disposed on at lo least oneof sides of the transparent polymer substrate, the transparentconductive layer has a outer surface containing micro bumps, wherein:

the transparent conductive laminate comprises a cross-linked polymerlayer (A) containing fine particles and a cross-linked polymer layer (B)between the transparent polymer substrate and the transparent conductivelayer, said cross-linked polymer layer (A) is between the transparentpolymer substrate and the cross-linked polymer layer (B); thecross-linked polymer layer (B) contacts the transparent conductivelayer; and the outer surface of said transparent conductive layercomprises the bumps having an average height of 0.3 to 1 μm and adensity in the range of 350 to 1,800 bumps/mm².

The transparent conductive laminate wherein the cross-linked polymerlayer (A) has a surface facing the cross-linked polymer layer (B), saidsurface comprises micro bumps having an average height of 0.3 to 1 μmand a density of 350 to 1,800 bumps/mm².

The transparent conductive laminate wherein the cross-linked polymerlayer (B) is 20 to 110 nm in thickness.

The transparent conductive laminate wherein the cross-linked polymerlayer (A) comprises a radiation-cured acrylic resin.

The transparent conductive laminate wherein the fine particles have anaverage diameter of 2 to 4 μm.

The transparent conductive laminate wherein the cross-linked polymerlayer (B) does not contain fine particles substantially.

The transparent conductive laminate wherein the cross-linked polymerlayer (B) is obtained by hydrolyzation and condensation polymerizationof a metal alkoxide.

The transparent conductive laminate wherein the transparent polymersubstrate is a film or sheet of a thermoplastic polymer.

The transparent conductive laminate wherein the transparent conductivelayer comprises mainly a metal oxide.

A transparent conductive laminate comprises a transparent polymersubstrate and a transparent conductive layer, said transparent polymersubstrate is a thermoplastic polymer film or sheet, said transparentconductive layer comprising mainly a metal oxide, wherein thetransparent conductive layer is disposed on one of sides, and thetransparent conductive layer has a surface containing micro bumps,further wherein: (1) the transparent conductive laminate comprises,between the transparent polymer substrate and the transparent conductivelayer, a radiation-cured resin layer (A1) which comprises an acrylicresin containing fine particles having an average diameter of 2 to 4 μm,and a cross-linked polymer layer (B1) which does not containing fineparticles substantially and obtained by hydrolyzation and condensationpolymerization of a metal alkoxide, said radiation-cured resin layer(A1) is disposed between said transparent polymer substrate and thecross-linked polymer layer (B1); (2) the cross-linked polymer layer (B1)has 20 to 110 nm in thickness and contacts with the transparentconductive layer; and (3) the transparent conductive layer has a surfacecontaining micro bumps having an average height of 0.3 to 1 μm and adensity of 350 to 1,800 bumps/mm².

The transparent conductive laminate further comprises a cross-linkedpolymer layer (C) disposed between the cross-linked polymer layer (A)containing fine particles and the cross-linked polymer layer (B), saidcross-linked polymer layer (C) has a higher refractive index than thatof the cross-linked polymer layer (B).

The transparent conductive laminate wherein the transparent conductivelayer has a surface having an average reflectance of not more than 5.5%in wavelength of 450 to 650 nm and a b* value of transmitted light being−2 to +3, wherein the b* value is obtained based on psychometric chromacoordinates in the CIE 1976 (L*a*b*) Space according to Japan IndustrialStandard No. Z8729.

The transparent conductive laminate wherein the cross-linked polymerlayer (C) has a refractive index at least 1.7 and not more than that of+0.3 higher than the refractive index of said transparent conductivelayer, and has 20 to 90 nm in thickness; the cross-linked polymer layer(B) has 1.35 to 1.5 in refractive index and 30 to 110 nm in thickness;the transparent conductive layer has 12 to 30 nm in thickness; and thecross-linked polymer layer (C), the cross-linked polymer layer (B) andthe transparent conductive layer have 180 to 230 nm in total of opticalpath length of each layer (wherein the optical path length is a valueobtained by multiplying a refractive index of a layer with a thicknessof the layer).

The transparent conductive laminate wherein the cross-linked polymerlayer (C) and the cross-linked polymer layer (B) are cross-linkedpolymer layers obtained by mainly hydrolyzation and condensationpolymerization of metal alkoxides, respectively.

The transparent conductive laminate wherein the cross-linked polymerlayer (C) has a refractive index in a range of 1.7 and +0.3 higher thanthe refractive index of the transparent conductive layer; thecross-linked polymer layer (B) has 1.35 to 1.5 in refractive index; thetransparent conductive layer has 12 to 30 nm in thickness; and thepolymer layer (B) has a minimum point of surface reflectance within awavelength range between 260 and 390 nm.

The transparent conductive laminate wherein the cross-linked polymerlayer (C) and the cross-linked polymer layer (B) are cross-linkedpolymer layers obtained by mainly hydrolyzation and condensationpolymerization of metal alkoxides, respectively.

A touch panel comprising two transparent electrode substrates, each ofwhich has a conductive layer at least one side of the substrate and thetransparent conductive layers of the two substrates face each other,characterized in that at least one of the transparent conductivesubstrates is the transparent conductive laminate according to claim 1.

The touch panel further comprises a transparent polymer film or sheetbeing laminated to a side opposite to the side where the transparentconductive layer of the transparent conductive laminate is formed.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schema showing the concrete touch panels of Examples 1 to 8and Comparative Examples 1 to 6.

FIG. 2 is a schema showing the concrete touch panels of Example 9 andComparative Example 7.

FIG. 3 is a schema showing the concrete touch panel of Example 10.

Explanation of the marks. 1 glass substrate 2 transparent conductivelayer 3 dot spacer 4 polyethylene terephthalate film or polycarbonatefilm 5 cross-linked polymer layer 6 cross-linked polymer layercontaining fine particles 7 cross-linked polymer layer 8 transparentconductive layer 9 cross-linked polymer layer 10 polarizer 11polycarbonate sheet

The transparent conductive laminate of the present invention ischaracterized that it has on at least one of sides of a transparentpolymer substrate a transparent conductive layer whose outer surface isfinely rough, and said surface comprises micro bumps having an averageheight in the range of 0.3 to 1 μm and a density in the range of 350 to1,800 bumps/mm².

The average height of the bumps was calculated by randomly selecting 10to 20 bumps from the bumps in a 250 μm square, individually measuringthe heights of the selected bumps and then determining the average valueof the measured heights of the bumps.

When said average height of the bumps exceeds 1 μm, the transparentconductive layer is peeled on the peripheries of the bumps withoutrelating to the density of the fine particles, thereby deteriorating theinputting performance of the touch panel (for example, the generation ofinputting errors, the insufficient accuracy of position detection). Whenthe average height of the bumps in the transparent conductive layersurface is controlled within the range of 0.3 to 1 μm, the peeling ofthe transparent conductive layer on the peripheries of the bumps iseliminated to improve the writing durability remarkably. When theaverage height of the bumps is below 0.3 μm, a problem of adhesion,between the electrode surface of the movable electrode substrate and theelectrode surface of the fixed electrode substrate, is caused tointerfere with the normal operation of the touch panel, and also aproblem of interference fringes generating between the movable electrodesubstrate and the fixed electrode substrate is caused to give anindistinct screen. The average height of the bumps is preferably in therange of 0.35 to 1.00 μm, more preferably in the range of 0.40 to 1.00μm.

Of course, it is not necessary that all of the heights of the bumps arecontrolled within the range of 0.3 to 1 μm. Even if the bumps havingheights of 0.1 to 0.3 μm or of 1.0 to 1.5 μm are somewhat contained, theeffects of the present invention are substantially not affected, whenthe average height of the bumps is controlled within the range of 0.3 to1 μm. However, the maximum height of the bumps is preferably not morethan 1.5 μm, more preferably not more than 1.2 μm, because the excessiveexistence of the bumps having high bump heights is not desirable fromthe viewpoint of the writing durability.

In addition, in order to prevent the generation of interference fringesbetween the movable electrode substrate and the fixed electrodesubstrate, it is important to control the density of the bumps in thesurface of the transparent conductive layer within the range of 350 to1,800 bumps/ mm². When the density of bumps is below 350 bumps/mm²,effects of preventing the generation of the interference fringes aresmall. On the other hand, the density exceeding 1,800 bumps/mm² are notpreferable, because a problem that the haze of the transparentconductive laminate is increased to give dim display letters difficultto read. The density of bumps is controlled preferably within the rangeof 400 to 1,600 bumps/mm², more preferably within the range of 450 to1,550 bumps/mm².

When the average height and the density of bumps in the surface of thetransparent conductive layer are 0.3 to 1 μm and 350 to 1,800 bumps/mm², respectively, preferably 0.35 to 1 μm and 400 to 1,600 bumps/mm²,respectively, the touch panel has excellent writing durability, does notcause the generation of interference fringes between the movableelectrode substrate and the fixed electrode substrate, and gives non-dimdisplay letters extremely easy to read.

The transparent polymer substrate composing the transparent conductivelaminate of the present invention will be explained.

The transparent polymer substrate suitably used in the present inventionis especially not limited, but it is preferable that the substrate hashigh transparency, concretely that the average value of the lighttransmittance of the substrate in the wavelength region of 400 to 700 nmis not less than 80%, especially not less than 85%.

When the transparent conductive laminate of the present invention isused as a movable electrode substrate, it is preferable that thetransparent conductive laminate is flexible. A film or sheet comprisinga thermoplastic polymer having good transparency is suitably used as thetransparent polymer substrate. Concretely, the film or sheet includesthe films or sheets of polyethylene terephthalate, polyethylenenaphthalate, a polycarbonate, a polyarylate, a polyethersulfone, apolysulfone, triacetylcellulose, diacetylcellulose, and a polyolefin.The film or sheet-like polymer substrate is suitably formed by a generalmelt-extruding method, a general solution casting method, or the like.If necessary, the substrate may uniaxially or biaxially be stretched toenhance the mechanical strengths and optical functions of thesubstrates. The substrate may, if necessary, be laminated to the same ordifferent kind of substrates through adhesives or glues.

The thickness of the transparent polymer substrate is in the range ofpreferably about 10 to 400 μm, more preferably 20 to 200 μm, from theview points of the operation characteristics, thinness and lightness ofthe touch panel, and so on. The surface opposite to the transparentconductive layer-disposed surface of the transparent conductive laminateof the present invention may be laminated to a plurality of transparentpolymer films or sheets through adhesives or glues to obtain ananti-scratching function, an anti-glare function, an anti-reflectionfunction, and so on, and the laminated transparent conductive laminatemay then be used as the movable electrode substrate of the touch panel.The transparent polymer films or sheets laminated to the surfaceopposite to the transparent conductive layer-disposed surface of thetransparent conductive laminate have thickness of preferably 20 to 400μm, more preferably 50 to 200 μm, the most preferably 70 to 200 μm,respectively.

When the transparent conductive laminate of the present invention isused as a movable electrode substrate, a fixed electrode substrate maybe a glass electrode substrate.

When the transparent conductive laminate of the present invention isalso used as a fixed electrode substrate, the flexibility is notessential, but a characteristic scarcely deformed by outer forces(rigidity) is rather sometimes needed in a certain use mode of the touchpanel. Thereby, the sheet of a thermosetting resin such as an epoxyresin or the sheet of an ultraviolet light-curable resin such as anacrylic resin in addition to the film or sheet of the above-mentionedthermoplastic resin may be used as the transparent polymer substrate ofthe transparent conductive laminate. A method for forming thetransparent polymer substrate includes an injection molding method and acasting polymerization molding method in addition to the above-mentionedmethods. If necessary, the transparent polymer substrate may belaminated to the same or different kind of transparent polymer film orsheet through adhesives or glues and then used. The thickness of thesubstrate obtained thus is preferably about 10 to 2,000 μm, morepreferably about 50 to 1,100 μm, the most preferably about 70 to 1,100μm.

In order to manufacture a touch panel suitable for portableinformation-processing equipment, the surface opposite to thetransparent conductive layer-disposed surface of the transparentconductive laminate of the present invention is rather preferably belaminated to a plurality of transparent polymer films or sheets throughadhesive or glues to give rigidity to the laminate, and the laminatedtransparent conductive laminate is then preferably be used as the fixedelectrode substrate of the touch panel. Thereby, the lightweight andinfrangible touch panel suitable for portable information-processingequipment is obtained. The thickness of the transparent polymer films orsheets laminated to the surface opposite to the transparent conductivelayer-disposed surface of the transparent conductive laminate ispreferably 50 to 2,000 μm, more preferably 70 to 2,000 μm and the mostpreferably 70 to 1,100 μm.

And, a new type touch panel having a structure in which a polarizer (ora polarizer and a retardation film) was laminated to the inputting side(user side) surface of the touch panel was recently developed. Theadvantage of the structure is to reduce the reflectance of extraneouslight in the touch panel to not more than a half and to improve thecontrast of the display in a state set to the touch panel.

Here, when the type of the touch panel is attached to a liquid crystaldisplay (LCD), a transparent polymer substrate characterized byexcellent optical isotropy is preferably used as the transparent polymersubstrate of the transparent conductive laminate, because polarizedlight passes through the electrode substrate. Concretely, an inplaneretardation value Re expressed by the equation: Re=(nx-ny)×d (nm) ispreferably at least 30 nm or less, more preferably 20 nm or less,wherein nx, ny and d (nm) are the refractive index of the transparentpolymer substrate in the slow axis direction, the refractive index inthe fast axis direction, and the thickness of the transparent polymersubstrate, respectively. Therein, the inplane retardation value of thetransparent polymer substrate is represented by a value measured using amulti-wavelength birefringence measurer (manufactured by Nihon BunkoCo., M-150) at a wavelength of 590 nm.

The film or sheet of a polycarbonate, an amorphous polyarylate, apolyethersulfone, a polysulfone, triacetylcellulose, diacetylcelluloseor an amorphous polyolefin or the sheet of a thermosetting resin such asan epoxy resin or the sheet of an ultraviolet light-curable resin suchas an acrylic resin among the lo above-mentioned films and sheets ispreferable as the transparent polymer substrate characterized byexcellent optical isotropy. The film or sheet of the polycarbonate, theamorphous polyarylate, the polyethersulfone, the polysulfone, or theamorphous polyolefin is most preferable from the viewpoint ofmoldability, production cost, thermal stability, and so on.

The polycarbonate includes polymers each containing at least onebisphenol compound selected from the group consisting of, for example,bisphenol A, 1,1-di(4-phenol)cyclohexylidene,3,3,5-trimethyl-1,1-di(4-phenyl)cyclohexylidene,fluorene-9,9-di(4-phenol) and fluorene-9,9-di(3-methyl-4-phenol) and thelike as a repeating unit monomer, their copolymers, and their mixtures,preferably a polycarbonate having an average molecular weight in therange of about 15,000 to 100,000 (for example, “Panlite” (produced byTeijin Kasei Co.), “Apec HT” (produced by Bayer AG.)).

And, the amorphous polyarylate includes “Elmec” (produced by KanegafuchiKagaku Kogyo K.K.), “U-polymer” (produced by Unitika Ltd.), and “Isaryl”(produced by Isonova Corp.).

Further, the amorphous polyolefin includes “Zeonor” (produced by NipponZeon Ltd.) and “Arton” (produced by JSR Corp.).

The method for producing the transparent polymer substrate includes amelt extrusion method, a solution casting method and an injectionmolding method. The transparent polymer substrate is especiallypreferably produced by the solution casting method from a viewpoint forobtaining excellent optical isotropy.

In the uses of the touch panel of the type that the polarized lightpasses through the exemplified electrode substrate, the value of thein-plane retardation values of the electrode substrate and thetransparent polymer substrate are very important, and thethree-dimensional refractive index characteristics of the electrodesubstrate and the transparent polymer substrate are additionallyimportant. Namely, when nz is the refractive index of the electrodesubstrate and the transparent polymer substrate in the film thickness lodirection, K value expressed by the equation: K={(nx+ny)/2−nz}×d ispreferably −250 to +150 nm, more preferably −200 to +100 nm, forobtaining the excellent viewing angle characteristic of the touch panel.

The transparent conductive laminate of the present invention has thefine particle-containing cross-linked polymer layer (A) on thetransparent conductive layer-disposed side of the above-mentionedtransparent polymer substrate.

Here, the fine particles include silica particles, cross-linked acrylicresin particles, and cross-linked polystyrene particles. The averagediameter of said fine particles is preferably 2 to 4 μm. When theaverage diameter of the fine particles exceeds 4 μm, the thickness ofthe cross-linked polymer layer needs to be enlarged and then dispersionof the thickness is increased. Due to large dispersion of the diameterof the fine particles and due to large dispersion of the thickness ofthe cross-linked polymer layer, it is consequently difficult to controlcoating conditions so that an average height of the bumps is included inthe range of 0.3 to 1 μm. The preferable average diameter of the fineparticles is 2.0 to 3.8 μm.

The fine particle-containing cross-linked polymer layer (A) of thepresent invention is usually the layer of a cross-linked polymerobtained by curing the particle-added layer of a monomer raw materialand/or an oligomer raw material by a polymerization reaction using heator radiation such as ultraviolet light or electron beams. Thecross-linked polymer includes organosilane polymers using siliconalkoxides such as methyltriethoxysilane and phenyltriethoxysilane asmonomer raw materials and/or oligomer raw materials, melaminethermosetting resins using etherified methylol melamines or the like asmonomer raw materials and/or oligomer raw materials, thermosettingresins such as phenoxy resins and epoxy resins, and radiation-curableresins using multi-functional acrylates such as polyolacrylates,polyesteracrylates, urethane acrylates and epoxy acrylates as monomerraw materials and/or oligomer raw materials. Among the cross-linkedpolymers, the radiation-curable polymers using the multi-functionalacrylate resins and so on are most preferably used, because thecross-linked polymer layer having high cross-link degrees is obtained inrelatively short times by the irradiation of radiation and because thecross-linked polymer layer is characterized by low loads on productionprocesses and by having a strong film strength. The diameters of saidfine particles, the mixing ratio of said particles with saidcross-linked polymer, the film thickness of said cross-linked polymerlayer and so on, are adjusted to control the average height of the bumpswithin the range of 0.3 to 1 μm.

The radiation-curable resin indicates a resin which is polymerized bythe irradiation of radiation such as ultraviolet light or electronbeams, and includes acrylic resins in whose each composition amulti-functional acrylate component having two or more acryloyl groupsin the unit structure is contained. For example, various acrylatemonomers such as trimethylolpropane triacrylate, trimethylolpropaneethylene oxide-modified triacrylate, trimethylolpropane propyleneoxide-modified triacrylate, isocyanuric acid ethylene oxide-modifiedtriacrylate, pentaerythritol tetraacrylate, dipentaerythritolpentaacrylate, dipentaerythritol hexaacrylate, anddimethyloltricyclodecane diacrylate, multi-functional acrylate oligomerssuch as polyester-modified acrylates, urethane-modified acrylates, andepoxy-modified acrylates, and so on, are preferable for the touch paneluses. The monomer raw materials and/or the oligomer raw materials may beused singly or after mixed with each other, and, if necessary, thehydrolytic condensation product of a silicon alkoxide is preferablyadded to the composition of the monomer raw materials and/or theoligomer raw materials in a proper amount.

Therein, when the resin layer is polymerized by the irradiation ofultraviolet light, a proper amount of a known photopolymerizationinitiator is added. The photopolymerization initiator includesacetophenone compounds such as diethoxyacetophenone,2-methyl-1-{4-(methylthio)phenyl}-2-morpholinopropane,2-hydroxy-2-methyl-1-phenylpropan-1-one, and1-hydroxycyclohexylphenylketone; benzoin compounds such as benzoin andbenyldimethylketal; benzophenone compounds such as benzophenone andbenzoylbenzoate; and thioxanthone compounds such as thioxanthone and2,4-dichlorothioxanthone.

The phenoxy thermosetting resin includes the thermally cross-linkedproduct of a phenoxy resin, phenoxy ether resin or phenoxy ester resinof the below-mentioned formula (1) with a multi-functional isocyanatecompound,

wherein, R¹ to R⁶ each means the same or different hydrogen or a C₁ toC₃ alkyl group; R⁷ means a C₂ to C₅ alkylene group; X means an ethergroup or an ester group; m means an integer of 0 to 3; n means aninteger of 20 to 300. Among the resins, a resin of the formula (1),wherein R¹, R² each is a methyl group; R³ to R⁶ each is a hydrogen; andR⁷ is a pentylene group, is preferable from the aspects of synthesiseasiness and productivity.

And, the multi-functional isocyanate is a compound having two or moreisocyanate groups in the molecule, including the following compounds.Polyisocyanates such as 2,6-tolylenediisocyanate,.2,4-tolylenediisocyaante, tolylenediisocyanate-trimethylolpropaneadduct, t-cyclohexane-1,4-diisocyanate, m-phenylenediisocyanate,p-phenylenediisocyanate, hexamethylenediisocyanate,1,3,6-hexamethylenetriisocyanate, isophoronediisocyanate,1,5-naphthalenediisocyanate, tolidinediisocyanate, xylylenediisocyanate,hydrogenated xylylenediisocyanate, diphenylmethane-4,4′-diisocyanate,hydrogenated diphenylmethane-4,4′-diisocyanate, lysinediisocyanate,lysine ester triisocyanate, triphenylmethanetriisocyanate,tris(isocyanatophenyl)thiophosphate, m-tetramethylxylylenediisocyanate,p-tetramethylxylylenediisocyanate, 1,6,11-undecanetriisocyanate,1,8-diisocyanato-4-isocyanatomethyloctane, bicycloheptanetriisocyanate,2,2,4-trimethylhexamethylenediisocyanate and2,4,4-trimethylhexamethylenediisocyanate, and their mixtures orpolyhydric alcohol adducts. Among the compounds,2,6-tolylenediisocyanate, 2,4-tolylenediisocyanate,tolylenediisocyanate-trimethylolpropane adduct andhexamethylenediisocyanate are especially preferable from the viewpointsof generality and reactivity.

Further, a tertiary amine such as known triethylenediamine or an organictin compound such as di-n-butyltindilaurate can be added in a properamount as a reaction accelerator to improve the rate of thecross-linking reaction.

And, for example, the thermally cross-linked product of a novolak typeepoxy resin expressed by the below-mentioned formula (2) is preferableas the epoxy thermosetting resin.

wherein, R⁸ indicates a hydrogen or a methyl group; R⁹ indicates ahydrogen or a glycidylphenyl ether group; and q indicates an integer of1 to 50, but since the value of q generally has a distribution and isdifficult to specify, q is preferably a large value as an averagenumber, more preferably not less than 3 or more, furthermore preferably5 or more.

A known curing agent is applied as a curing agent for cross-linking theepoxy resin. For example, a curing agent such as an amine-based curingagent, a polyaminoamide-based curing agent, an acid and an acidanhydride, imidazole, a mercaptan, or a phenolic resin is used. Amongthe curing agents, preferably an acid anhydride or an alicyclic aminecompound, more preferably an acid anhydride, is used. The acid anhydrideincludes alicyclic acid anhydrides such as methylhexahydrophthalic acidanhydride and methyltetrahydrophthalic anhydride, aromatic acidanhydrides such as phthalic acid anhydride, and aliphatic acidanhydrides such as dodecylphthalic acid anhydride, especially preferablymethylhexahydrophthalic acid anhydride. Further, the alicyclic amineincludes bis(4-amino-3-methyldicyclohexyl)methane,diaminocyclohexylmethane and isophoronediamine, especially preferablybis(4-amino-3-methyldicyclohexyl)methane.

Here, when an acid anhydride is used as a curing agent, a reactionaccelerator for accelerating the curing reaction of an epoxy resin withthe acid anhydride may be added. The reaction accelerator includes knownsecondary and tertiary amines such as benzylmethyamine,2,4,6-tris(dimethylaminomethyl)phenol, pyridine, and1,8-diazabicyclo(5,4,0)undecene-1, and imidazole compounds.

And, the polymer of the silicon alkoxide is preferably obtained from amixture of two or more di- to tetra-functional, more preferably tri- totetra-functional, silicon alkoxides or from an oligomer obtained bypreliminarily suitably hydrolyzing and dehydrating-condensing themixture in a solution.

The silicon alkoxide includes tetramethoxysilane, tetraethoxysilane,methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane,γ-glycidoxypropyltrimethoxysilane,β(3,4-epoxycyclohexyl)ethyltrimethoxysilane, vinyltrimethoxysilane,N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane,N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, andγ-aminopropyltriethoxysilane.

The silicon alkoxides are thermally polymerized, and, if necessary, thecross-linkage degree of the obtained polymer can be enhanced byirradiating the coating film of the polymer with active light such asultraviolet light.

A proper anchor layer is disposed on or above the transparent polymersubstrate and is between the particle-containing cross-linked polymerlayer (A) and the transparent polymer substrate. The anchor layerpreferably includes the following layers. (1) A layer having a functionfor improving the adhesivity of said polymer layer to the substrate, (2)various phase difference compensation layers such as a layer whosethree-dimensional refractive index characteristic gives negative Kvalue, (3) a layer having a viscoelastic characteristic for relaxingstresses (vertical stress, horizontal stress) added to a substrate, suchas the layer that the storage elastic modulus is about 1 kg/mm² or lessat a temperature near to room temperature, (4) a layer having a functionfor preventing the permeation of moisture and air or a function forabsorbing moisture and air, (5) a layer having a function for absorbingultraviolet light and infrared light, and (6) a layer having a functionfor lowering the electrification property of the substrate.

The method for forming the fine particle-containing cross-linked polymerlayer (A) of the present invention comprises adding the fine particlesto the above-mentioned monomer raw material and/or the above-describedoligomer raw material, if necessary, further adding aphotopolymerization initiator, a curing agent, a catalyst, and so on,dissolving the mixture in one of a proper organic solvent or more,adjusting the concentration and viscosity of the solution to prepare acoating liquid, coating the coating liquid on the transparent polymersubstrate, and then curing the coating layer by the irradiation ofradiation, a thermal treatment or the like. The coating method includesvarious coating methods such as a microgravure coating method, a Mayerbar coating method, a direct gravure coating method, a reverse rollcoating method, a curtain coating method, a die coating method, a knifecoating method and a spin coating method.

When the cross-linked polymer layer (B) is disposed on or above theparticle-containing cross-linked polymer layer (A) and is between theparticle-containing cross-linked polymer layer (A) and the transparentconductive layer according to the present invention, the opticalcharacteristics and mechanical characteristics of the transparentconductive laminate are improved. Therein, the cross-linked polymerlayer (B) is preferably prepared by hydrolyzing and condensationpolymerizing a metal alkoxide. Titanium alkoxides, zirconium alkoxidesand silicon alkoxides are preferable among the metal alkoxides fromviewpoints such as excellent mechanical strengths, excellent stability,excellent adhesivity to the transparent conductive layer, the substrate,and so on. The embodiments of the metal alkoxides and the method forforming the cross-linked polymer layer (B) will be mentioned later. Andtwo or more kinds of the monomer raw materials and/or the oligomer rawmaterials may be mixed with each other and then used.

The cross-linked polymer layer (B) may contain an additive such as fineparticles, but it is preferable that the cross-linked polymer layer (B)does substantially not contain the additive, because it is difficult tocontrol the heights of the bumps and the density of the bumps in thesurface of the transparent conductive layer and because the strength ofthe cross-linked polymer layer (B) is weakened, when the cross-linkedpolymer layer (B) contains the additive.

When only the cross-linked polymer layer (B) is disposed between theparticle-containing cross-linked polymer layer (A) and the transparentconductive layer, the thickness of the cross-linked polymer layer (B) ispreferably not less than 20 nm, more preferably not less than 25 nm,furthermore preferably not less than 30 nm. When the thickness of thelayer (B) is less than 20 nm, the effect for improving the opticalcharacteristics and mechanical characteristics of the transparentconductive laminate is small. The upper limit of the thickness of thelayer (B) is preferably not more than 110 nm, more preferably not morethan 100 nm. When the thickness of the layer (B) exceeds 110 nm, theoptical characteristics and mechanical characteristics of thetransparent conductive laminate are sometimes contrarily deteriorated.

A cross-linked polymer layer (C) having a larger refractive index thanthat of the cross-linked polymer layer (B) can be disposed between theparticle-containing cross-linked polymer layer (A) and the cross-linkedpolymer layer (B) to lower the reflectance of the transparent conductivelaminate in the visible light region to improve the transmittance. Inthe case, the total of optical path length of the three layers of thecross-linked polymer layer (C), the cross-linked polymer layer (B), andthe transparent conductive layer is preferably adjusted to give anaverage reflectance of not more than 5.5% in wavelengths of 450 to 650nm on the surface of the transparent conductive layer and give the b*value of transmitted light in the range of −2 to +3 as the b* valuebased on psychometric chroma coordinates in the CIE 1976 (L*a*b*) Spaceaccording to Japan Industrial Standard No. Z8729. When the averagereflectance and the b* value are adjusted to 5.5% or less and the rangeof −2 to +3, respectively, the visibility of a display is substantiallynot deteriorated, even when the touch panel is attached to the display.

Conditions for realizing the above-mentioned average reflectance and theabove-mentioned b* value are as follows.

Namely, (1) the cross-linked polymer layer (C) has a refractive index ina range of from 1.7 to +0.3 higher than the refractive index of thetransparent conductive layer, and is in a range of from 20 to 90 nm inthickness; the cross-linked polymer layer (B) has a refractive index ina range of from 1.35 to 1.5 and is in a range of from 30 to 110 nm inthickness; the transparent conductive layer has a thickness of 12 to 30nm; and the cross-linked polymer layer (C), the cross-linked polymerlayer (B) and the transparent conductive layer have a value of 180 to230 nm in total of optical path length of the above three layers(wherein the optical path length is a value obtained by multiplying arefractive index of a layer with a thickness of the layer).

Or, (2) the cross-linked polymer layer (C) has a refractive index in arange of from 1.7 to +0.3 higher than the refractive index of thetransparent conductive layer; the cross-linked polymer layer (B) has arefractive index in a range of from 1.35 to 1.5; the transparentconductive layer has 12 to 30 nm in thickness; and the polymer layer (B)has a minimum point of surface reflectance within a wavelength rangebetween 260 and 390 nm.

The cross-linked polymer layer (C) and the cross-linked polymer layer(B) preferably comprise cross-linked polymer layers obtained by mainlyhydrolyzing and condensation polymerizing metal oxides, respectively.Among the cross-linked polymer layers obtained by hydrolyzation andcondensation polymerization of the metal oxides, polymer layers obtainedby hydrolyzing and condensation polymerizing titanium alkoxides,zirconium alkoxides and silicon alkoxides are preferable from viewpointsthat the mechanical strengths, stability, and so on, of the polymerlayers and the adhesivity of the polymer layers to the transparentconductive layers, the cross-linked polymer layers, and the like, areexcellent.

The titanium alkoxides includes titanium tetraisoproxide, tetra-n-propylortho titanate, titanium tetra-n-butoxide, and tetrakis(2-ethylhexyloxy)titanate. The zirconium alkoxide includes zirconium tetraisopropoxide,and zirconium tetra-n-butoxide.

The silicon alkoxide includes tetramethoxysilane, tetraethoxysilane,methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane,γ-glycidoxypropyltrimethoxysillane,β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, vinyltrimethoxysilane,N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane,N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, andγ-aminopropyltriethoxysilane. If necessary, two or more kinds of thesilicon alkoxides are preferably mixed and used in many cases from theviewpoints of the mechanical strengths, adhesivity, solvent resistance,and so on, of the layers, and it is especially preferable that thesilicon alkoxides having amino groups in the molecules are contained inan amount of 0.5 to 60 percent by weight in the whole composition of thesilicon alkoxides.

The metal alkoxides may be used as the monomers as such or as oligomersafter preliminarily suitably subjected to hydrolysis reactions anddehydrating condensation polymerization reactions. Usually, the metalalkoxides are dissolved and diluted with one or more proper organicsolvents, and the obtained coating liquid is then coated on a substrate.The coating film formed on the substrate is hydrolyzed with moisture inair or the like and then dehydrated and condensation polymerized. Aproper heating treatment is generally necessary for the acceleration ofthe condensation polymerization reaction, and in the process of acoating method, it is preferable that a heating treatment at atemperature of not less than 100° C. for several minutes or more isapplied. And, if necessary, the above-mentioned thermal treatment andthe irradiation of active light such as ultraviolet light on the coatingfilm may simultaneously be carried out to enhance the cross-linkingdegree of the coating film.

As the diluting solvent, an alcoholic solvent or a hydrocarbon-basedsolvent, such as ethanol, 2-propanol, butanol, 2-methyl-1-propanol,1-methoxy-2-propanol, hexane, cyclohexane, or ligroin is suitable, and apolar solvent such as xylene, toluene, cyclohexanone,methylisobutylketone or isobutyl acetate may also be used. The solventsmay be used singly or as a mixed solvent comprising two or more kinds ofthe solvents.

The transparent conductive layer of the present invention is disposed onthe above-mentioned cross-linked polymer layer (B). The transparentconductive layer comprises mainly a metal oxide. From needs for thereduction in the electric power consumption of the touch panel and onthe processing of circuits, and so on, it is preferable to use atransparent conductive layer exhibiting a surface resistance value inthe range of preferably 100 to 2,000 Ω/▪, more preferably 150 to2,000Ω/▪, at a film thickness of 12 to 30 nm. When the thickness of thetransparent conductive layer is below 12 nm, the thickness is notpreferable, because the stability of the resistance value with thepassage of time tends to be inferior, while the thickness exceeding 30nm is also not preferable, because the transmittance of the transparentconductive laminate is lowered.

Said metal oxide includes tin oxide containing antimony or the like,indium tin oxide (ITO), and indium zinc oxide. And, the transparentconductive layer may further contain one or more kinds of metal oxidessuch as silicon dioxide, titanium dioxide, aluminum trioxide, zirconiumdioxide and zinc oxide.

The transparent conductive layer can be formed by a known physical vapordeposition (PVD) such as a sputtering method, an ion plating method, ora vacuum evaporation method, or a CVD method. In particular, thesputtering method is preferable from the aspects of the uniformity ofthe thickness and composition of the transparent conductive layer in thetransverse direction (TD) and the machine direction (MD).

In order to prevent the scratching or solvent damage of a transparentpolymer substrate in a process for manufacturing a touch panel or in ausing mode of the touch panel attached to a display, it is preferable todispose a cross-linked polymer layer having a hard coat property and/ora solvent-resistant property on the opposite side of the transparentpolymer substrate to the transparent conductive layer-disposed side.Fine particles may be added to the cross-linked polymer layer to imparta slipping property, an interference fringe-preventing property and ananti-glare property. The cross-linked polymer includes theradiation-curable resins such as the acrylic resins, the thermosettingresins such as the phenoxy resins and the epoxy resins, and the siliconalkoxide polymers, as mentioned above. Among the cross-linked polymers,the radiation-curable resins such as the acrylic resins are mostpreferably used, because the cross-linked polymer layer having highcross-link degrees is obtained in relatively short times by theirradiation of radiation and because the cross-linked polymer layer ischaracterized by low loads on production processes and by having astrong film strength.

A proper anchor layer is disposed on the transparent polymer substrate,and is between the cross-linked polymer layer and the transparentpolymer substrate. The anchor layer includes the same anchor layers asthose used for the above-mentioned particles-containing cross-linkedpolymer layer (A).

A method for forming the cross-linked polymer layer also includes thesame methods as those for forming the above-mentionedparticles-containing cross-linked polymer layer (A).

EXAMPLES

The present invention will be explained hereafter in more detail withexamples, but methods for evaluating average height of bumps, density ofbumps, ten point height (Rz), and writing durability of the outersurface of the transparent conductive layer are as follows.

Average bump height, bump density

The average height of bumps was obtained by randomly selecting ten totwenty bumps in a 250 μm square by the use of a real time scanning typelaser microscope (manufactured by Laser Tech Corp., 1LDM21D),individually measuring the heights of the bumps and then calculating theaverage height of the bumps. The density of the bumps (the number ofbumps per unit area) was also calculated.

Ten Point Height

Ten point height (Rz) was measured using a stylus type differencethickness meter (manufactured by Sloan Corp, Dektak 3).

The measurement was carried under measuring conditions comprising ameasuring length of 2 mm, a measuring speed of 4.8 mm/minute, 1,000data, and a 20 μm high pass filter.

Writing Durability

The transparent conductive laminate of the present invention and a glasselectrode substrate were used as a movable electrode substrate and afixed electrode substrate, respectively, to manufacture a touch panel.But, the transparent conductive laminate of the present invention wasused as a fixed electrode substrate in Example 10. Then, katakana(square Japanese characters) were written in the order of the katakanasyllabary in a 20 mm square area on the outer central surface of themovable electrode substrate of the touch panel by the use of apolyacetal resin pen having a 0.8R tip. The writing pressure load of thepen was 250 g. linearity was measured for each 50,000 letter-writtentime. The number of the written letters until the linearity exceeds 1.5%was defined to be writing durability.

A method for measuring the linearity was as follows.

A direct current voltage of 5V was applied between parallel electrodeson the movable electrode substrate or on the fixed electrode substrate.Electric voltages were measured at a distance of 5 mm in the directionvertical to the parallel electrodes.

ET=(EB−EA)·X/(B−A)+EA

L(%)=(|ET−EX|)/(EB−EA)·100

Wherein EA is the voltage at a measurement-started position A; EB is thevoltage of a measurement-finished position; EX is an observed voltagevalue at a distance of X from the position A; ET is a theoretical value;L is linearity.

Examples 1 Through 3, Comparative Examples 1 Through 3

FIG. 1 is a touch panel showing an example of the present invention. InFIG. 1, 1 is a glass substrate; 2 and 8 are transparent conductivelayers; 3 is a dot spacer; 4 is a polyethylene terephthalate (PET) film;5 is a cross-linked polymer layer; 6 is a particle-containingcross-linked polymer layer; and 7 is a cross-linked polymer layer. Afixed electrode substrate A comprises the glass substrate 1, thetransparent conductive layer 2, and the dot spacer 3. A movableelectrode substrate comprises the PET film 4, the cross-linked polymerlayer 5, the particle-containing cross-linked polymer layer 6, thecross-linked polymer layer 7 and the transparent conductive layer 8.

The touch panel was manufactured as follows. SiO₂ layers were disposedon both the surfaces of the 1.1 mm-thick glass substrate 1 by a dipcoating method, and a 18 nm-thick ITO layer was then disposed as thetransparent conductive layer 2 by a sputtering method. The dot spacer 3having a height of 7 μm, a diameter of 70 μm and a pitch of 1.5 mm wasdisposed on the ITO layer to manufacture the fixed electrode substrate.

On the other hand, a 188 μm-thick PET film (produced by Teijin Ltd.,OFW) was prepared as a transparent polymer substrate.

Then, for the formation of the cross-linked polymer layer 5, a coatingliquid L comprising 50 parts by weight of a polyester acrylate (producedby Toa Kagaku Kabushiki Kaisha, Alonix M8060), 50 parts by weight ofdipentaerythritol hexaacrylate (produced by Nippon Kayaku KabushikiKaisha, DPHA), 7 parts by weight of a photocuring initiator (produced byCiba-Geigy, Irgacure 184), and 200 parts by weight of1-methoxy-2-propanol as a diluent. The coating liquid L was coated onone surface of the PET film, and then dried for 1 minute at 60° C. Theproduced coating film was irradiated and cured with light by the use ofa high pressure mercury lamp having a strength of 160 w/cm in acondition comprising an integrated light quantity of 450 mJ/cm² todispose the cross-linked polymer layer 5 (thickness: about 3 μm).

Subsequently, the above-mentioned coating liquid L for the cross-linkedpolymer layer 5 was mixed with a prescribed amount of either of siliconcross-linked particles (produced by GE Toshiba Silicone Co., Tospearl130) having an average diameter of about 3 μm, acryl cross-linkedparticles (Negami Kogyo Kabushiki Kaisha, Artpearl F5P) having anaverage diameter of about 3.4 μm, and silicone cross-linked particles(GE Toshiba Silicone Co., Tospearl 145) having an average diameter ofabout 4.5 μm to obtain various coating liquids L′ for the cross-linkedpolymer layers 6. Either of the coating liquids L′ was coated on thenon-coated surface (the surface on which the above-mentionedcross-linked polymer layer 5 was not disposed) of the PET film so as togive a thickness of about 2 to 3 μm after cured. The coated coatingliquid L′ was dried at 60° C. for 1 minute and then irradiated withlight by the use of a high pressure mercury lamp lo having a strength of160 w/cm in a condition comprising an integrated light quantity of 450mJ/cm² to form the particle-containing cross-linked polymer layer 6.

Thus, in Examples, various particle-containing cross-linked polymerlayers having different average heights of the bumps and differentdensities of the bumps were formed by changing the particle diameters ofthe fine particles added thereto, the amounts of the fine particles andthe thicknesses of the particle-containing cross-linked polymer layers.

Subsequently, a coating liquid M for the cross-linked polymer layer 7was prepared by the following procedure. Namely, 720 parts by weight ofwater, 1,080 parts by weight of 2-propanol and 46 parts by weight ofacetic acid were mixed with each other, further successively mixed with480 parts by weight of γ-glycidoxypropyltrimethoxysilane (produced byShinetsu Chem. Ind. Co., KBM 403), 240 parts by weight ofmethyltrimethoxysilane (produced by Shinetsu Chem. Ind. Co., KBM 13) and120 parts by weight of N-β(aminoethyl)-γ-aminopropyltrimethoxysilane(produced by Shinetsu Chem. Ind. Co., KBM 603), and then stirred forthree hours to hydrolyze and partially condense the alkoxysilane mixtureliquid. The product was diluted with the 1:1 weight ratio mixture of2-propanol with 1-methoxy-2-propanol to prepare the coating liquid M forthe cross-linked polymer layer 7. The coating liquid M was coated on theabove-mentioned particle-containing cross-linked polymer layer 6 andthen thermally treated at 130° C. for five minutes to form thecross-linked polymer layer 7 having a thickness of about 35 nm.

Subsequently, the transparent conductive layer 8 was disposed to theabove-mentioned polymer layer 7. As the transparent conductive layer 8,an indium tin oxide (ITO) layer was formed in a thickness of about 20 nmby a DC magnetron sputtering method. An ITO target comprising indiumoxide and tin oxide in a 95:5 weight ratio and having a packing densityof 98% was used as the target. The above-mentioned film was set to theinside of a sputtering machine, and the sputtering machine was evacuatedto a pressure of 1.3 mPa and then charged with a 98.5:1.5 volume ratiomixture gas of Ar with O₂ to give an inner atmospheric pressure of 0.27Pa. The set film was subjected to a sputtering treatment underconditions comprising a substrate temperature of 50° C. and a makingpower density of 1 W/ m² to deposit the ITO layer as the transparentconductive layer 8 on the above-mentioned cross-linked polymer layer 7.The surface resistance of the transparent conductive layer was about 300Ω/▪.

The transparent conductive laminate obtained thus was used as a movableelectrode substrate.

And, as Comparative Example 3, a movable electrode substrate wasmanufactured by directly depositing the ITO layer on theparticle-containing cross-linked polymer layer 6 without disposing thecross-linked polymer layer 7.

The movable electrode substrate and the fixed electrode substrate wereused to manufacture the touch panel showed in FIG. 1. Therein, FIG. 1 isa conception diagram showing a part of the structure, and a peripheralinsulating layer, an adhesive layer and a leading circuit to outsideswere omitted.

The average heights of bumps, the densities of bumps, ten point height(Rz) and writing durability test results of the transparent conductivelayer (ITO layer) surfaces of the movable electrode substrates are shownin Table 1.

TABLE 1 Fine particles States of ITO layer surface Evaluation *1 *2 *3*4 *5 *6 *7 *8 Example 1 3.0 0.7 0.49 0.65 0.34 820 0.22 >15 Example 23.0 1.4 0.60 0.82 0.47 1170 0.19 >15 Example 3 3.4 1.4 1.00 1.11 0.90900 0.24 15 Comparative 3.4 1.0 1.06 1.33 0.78 700 0.33 5 Example 1Comparative 4.5 0.4 1.15 1.59 0.90 300 0.28 <5 Example 2 Comparative 3.41.4 1.00 1.11 0.90 900 0.24 <5 Example 3 *1 average diameter (μm). *2addition amount (parts by weight in solid content). *3 average height ofbumps (μm). *4 maximum height of bumps (μm). *5 minimum height of bumps(μm). *6 density of bumps (bumps/mm²). *7 Rz (μm). *8 writing durability(10,000 times)

Examples 4 Through 8, Comparative Examples 4 Through 6

Various transparent conductive laminates were manufactured similarly asin Examples 1 through 3. The transparent conductive laminates were usedas movable electrode substrates to manufacture the touch panels of FIG.1. The outer surfaces of the movable electrode substrates were pushedwith a finger to bring the movable electrode substrates into contactwith the fixed electrode substrates, and the states of interferencefringes generated with a three band phosphor type fluorescent lamp wereobserved from the sides of the fixed electrode substrates. Theevaluation results are shown in Table 2. And, the touch panels wereattached to LCDs, and easiness degrees in seeing letters were observed.The evaluation results are shown in Table 3.

TABLE 2 Fine particles States of ITO layer surface Evaluation *1 *2 *3*4 *5 *6 *7 *9 Example 4 3.0 1.7 0.73 0.84 0.60 1550 0.23 nothingExample 5 3.0 1.4 0.60 0.82 0.47 1170 0.19 nothing Example 6 3.0 1.00.64 0.72 0.52 1080 0.27 nothing Example 7 3.0 0.7 0.55 0.82 0.39 8500.22 nothing Comparative 3.0 0.15 0.66 1.06 0.36 210 0.11 slightlyExample 4 existent Comparative 3.0 1.4 0.28 0.36 0.19 1340 0.09 existentExample 5 *1 average diameter (μm). *2 addition amount (parts by weightin solid content). *3 average height of bumps (μm). *4 maximum height ofbumps (μm). *5 minimum height of bumps (μm). *6 density of bumps(bumps/mm²). *7 Rz (μm). *9 influence fringe

TABLE 3 Fine particles States of ITO layer surface Evaluation *1 *2 *3*4 *5 *6 *7 *10 Example 8 3.0 1.4 0.60 0.82 0.47 117 0.19 goodComparative 3.0 2.3 0.77 0.88 0.67 2070 0.24 dim Example 6 *1 averageparticle diameter (μm). *2 addition amount (parts by weight in solidcontent). *3 average height of bumps (μm). *4 maximum height of bumps(μm). *5 minimum height of bumps (μm). *6 density of bumps (bumps/mm²).*7 Rz (μm). *10 easiness degree in seeing letters

Example 9, Comparative Example 7

FIG. 2 is a touch panel showing an example of the present invention. InFIG. 2, 1 is a glass substrate; 2 and 8 are transparent conductivelayers; 3 is a dot spacer; 4 is a polycarbonate (PC) film; 5 is across-linked polymer layer; 6 is a particle-containing cross-linked lopolymer layer; 7, 9 are cross-linked polymer layers; and 10 is apolarizer. A fixed electrode substrate comprises the glass substrate 1,the transparent conductive layer 2, and the dot spacer 3. A movableelectrode substrate comprises the polarizer 10, the PC film 4, thecross-linked polymer layer 5, the particle-containing cross-linkedpolymer layer 6, the cross-linked polymer layers 7, 9 and thetransparent conductive layer 8. In order to manufacture the touch panel,the fixed electrode substrate was manufactured by the same method as inExamples 1 through 3.

In Example 9, a 100 μm-thick PC film (produced by Teijin Ltd., Pureace)was used instead of the PET film as the transparent polymer substrate.The others were carried out similarly as in Example 2, and fineparticles having an average diameter of 3 μm were used. Thus, thecross-linked polymer layer 5 (thickness: about 3 μm) and theparticle-containing cross-linked polymer layer 6 (thickness: about 2.6μm) were disposed on one surface and the other surface of the PC film,respectively.

Subsequently, a coating liquid N for the cross-linked polymer layer 9was prepared by the following procedure. Namely, the coating liquid Nfor the cross-linked polymer layer 9 was prepared by dilutingtetrabutoxytitanate (produced by Nihon Soda Co., B-4) with a mixturesolvent of ligroin with butanol. The coating liquid N for thecross-linked polymer layer 9 was coated on the particle-containingcross-linked polymer layer 6 and then thermally treated at 130° C. fortwo minutes to form the cross-linked polymer layer 9 having a thicknessof about 41 nm and a refractive index of about 1.82.

Further, the coating liquid M in Example 1 was used as a coating liquidfor the cross-linked polymer layer 7. The coating liquid M was coated onthe cross-linked polymer layer 9 and then thermally treated at 130° C.for 5 minutes to form the cross-linked polymer layer 7 having athickness of about 51 nm and a refractive index of about 1.47. Theminimum wavelength of the surface reflectance of the cross-linkedpolymer layer 7 was 300 nm.

Then, the transparent conductive layer 8 was disposed on thecross-linked polymer layer 7 to form the laminate similarly as inExample 1. The surface resistance of the transparent conductive layer ofthe electrode substrate for Example 9 was about 300 Ω/▪, and the averageheight and density of bumps in the surface of the transparent conductivelayer were 0.6 μm and 1,170 bumps/ mm², respectively. The laminate wasused as the movable electrode substrate of Example 9.

And, in Comparative Example 7, a 100 μm-thick PC film (produced byTeijin Ltd., Pureace) was used instead of the PET film as thetransparent polymer substrate. The others were carried out similarly asin Comparative Example 2, and fine particles having an average diameterof 4.5 μm were used. Thus, the cross-linked polymer layer 5 (thickness:about 3 μm) and the particle-containing cross-linked polymer layer 6(thickness: about 3.1 μm) were disposed on one surface and the othersurface of the PC film, respectively. Subsequently, the coating liquid Nfor the cross-linked polymer layer 9 was coated on theparticle-containing cross-linked polymer layer 6 and then thermallytreated at 130° C. for two minutes to form the cross-linked polymerlayer 9 having a thickness of about 41 nm and a refractive index ofabout 1.82. Further, the coating liquid M of Example 1 was used as acoating liquid for the cross-linked polymer layer 7. The coating liquidM was coated on the cross-linked polymer layer 9 and then thermallytreated at 130° C. for 5 minutes to form the cross-linked polymer layer7 having a thickness of about 51 nm and a refractive index of about1.47. The minimum wavelength of the surface reflectance of thecross-linked polymer layer 7 was 300 nm.

Subsequently, the transparent conductive layer 8 was formed on thecross-linked polymer layer 7 to form the laminate similarly as inExample 1. The surface resistance of the transparent conductive layer ofthe electrode substrate for Comparative Example 7 was about 300 Ω/▪, andthe average height and density of bumps in the surface of thetransparent conductive layer were 1.15 μm and 300 bumps/mm²,respectively. The laminate was used as the movable electrode substrateof Comparative Example 7.

The electrode substrate, a fixed electrode and a polarizer (produced bySanrittsu K.K., LLC2-9218AGHSF) were used to manufacture a touch panelshown in FIG. 2. Therein, FIG. 2 is a conception diagram showing a partof the structure, and a peripheral insulating layer, an adhesive layerand a leading circuit to outsides were omitted.

The writing durability of the touch panel of Example 9 was 200,000 timesand extremely excellent.

On the other hand, the writing durability of the touch panel ofComparative Example 7 was 50,000 times and inferior.

Example 10

FIG. 3 is a touch panel showing an example of the present invention. InFIG. 3, 3 is a dot spacer; 4 is a PET film or PC film; 5 is across-linked polymer layer; 6 is a particle-containing cross-linkedpolymer layer; 7, 9 are cross-linked polymer layers; 8 is a transparentconductive layer; and 11 is a PC sheet. A fixed electrode substratecomprises the PC sheet 11, the PC film 4, the cross-linked polymer layer5, the particle-containing cross-linked polymer layer 6, thecross-linked polymer layers 7, 9, the transparent conductive layer 8 anda dot spacer 3. A movable electrode substrate comprises the PET film 4,the cross-linked polymer layer 5, the cross-linked polymer layer 7 andthe transparent conductive layer 8.

The movable electrode substrate of the touch panel was manufactured bythe following method. The coating liquid L used in Example 1 was coatedon one surface of a 188 μm-thick PET film (produced by Teijin Ltd., OFW)as a transparent polymer substrate. The coating film was dried at 60° C.for one minute and then cured by the irradiation of light in a conditioncomprising an integrated light quantity of 450 mJ/cm² by the use of ahigh pressure mercury lamp having a strength of 160 w/cm to dispose thecross-linked polymer layer 5 (thickness: about 3 μm). Similarly, across-linked polymer layer 5 (thickness: about 3 μm) was disposed on theopposite side of the PET film.

Subsequently, the coating liquid M used in Example 1 was coated on oneof the cross-linked polymer layers 5 and then thermally treated at 130°C. for five minutes to form the cross-linked polymer layer 7 having athickness of about 35 nm.

Subsequently, the transparent conductive layer 8 was disposed to thecross-linked polymer layer 7 to form a movable electrode substrate bythe same method as in Example 1. The surface resistance of thetransparent conductive layer 8 was about 300 Ω/▪.

Then, the fixed electrode substrate was manufactured as follows.

Similarly in Example 9, a 100 μm-thick PC film (produced by Teijin Ltd.,Pureace) was used as a transparent polymer substrate, and thecross-linked polymer layer 5 (thickness: about 3 μm) and theparticle-containing cross-linked polymer layer 6 (thickness: about 2.6μm) were disposed on one surface and the other surface of the PC film,respectively.

Subsequently, by the same method as in Example 9, the cross-linkedpolymer layer 9 having a thickness of about 41 nm and a refractive indexof about 1.82 was formed on the particle-containing cross-linked polymerlayer 6, and the cross-linked polymer layer 7 having a thickness ofabout 51 nm and a refractive index of about 1.47 was formed on thecross-linked polymer layer 9. The minimum wavelength of the surfacereflectance of the cross-linked polymer layer 7 was 300 nm.

Successively, similarly as in Example 1, the transparent conductivelayer 8 having a thickness of about 22 nm and a refractive index ofabout 2.0 was disposed to the cross-linked polymer layer 7 to form theelectrode substrate. The surface resistance of the transparentconductive layer of the electrode substrate was about 300 Ω/▪, and theaverage height and the density in the surface of the transparentconductive layer were 0.6 μm and 1,170 bumps/ mm², respectively. The b*value of psychometric chroma coordinates of transmitted light in the CIE1976 (L*a*b*) Space was +0.6.

Then, a 1 mm-thick PC sheet (produced by Teijin Chem. Ltd., Panlite) 11was adhered to the surface of the cross-linked polymer layer 5 on theopposite side of the electrode substrate to the side on which thetransparent conductive layer 8 was disposed. Further, the dot spacer 3having a height of 7 μm, a diameter of 70 μm and a pitch of 1.5 mm wasdisposed on the transparent conductive layer 8 to form the fixedelectrode substrate.

The movable electrode substrate and the fixed electrode substrate wereused to form the touch panel shown in FIG. 3. Therein, the presentFigure is a conception diagram showing a part of the structure, and aperipheral insulating layer, an adhesive layer and a leading circuit tooutsides were omitted.

The writing durability of the touch panel was 150,000 times andexcellent. Further, the touch panel has characteristics that the touchpanel is lightweight and is not broken down, even when dropped.

Utilization in Industry

As mentioned above, since the average height of bumps and the density ofbumps in the surface of the transparent conductor layer are 0.3 to 1 μmand 350 to 1,800 bumps/ mm², respectively, the transparent conductivelaminate of the present invention can be used as an electrode substrateto provide a touch panel which has excellent writing durability, doesnot generate an interference fringe in the touch panel, does not makethe letters of the display dim, and gives extremely easily readableletters.

What is claimed is:
 1. A transparent conductive laminate comprising atransparent polymer substrate and a transparent conductive layerdisposed on at least one of sides of the transparent polymer substrate,said transparent conductive layer has a surface containing micro bumps,wherein: (1) said transparent conductive laminate comprises across-linked polymer layer (A) containing fine particles and across-linked polymer layer (B) between the transparent polymer substrateand the transparent conductive layer, said cross-linked polymer layer(A) is disposed between the transparent polymer substrate and saidcross-linked polymer layer (B); (2) the cross-linked polymer layer (B)contacts the transparent conductive layer; and (3) the surface of saidtransparent conductive layer comprises the bumps having an averageheight of 0.3 to 1 μm and a density in the range of 350 to 1,800bumps/mm².
 2. The transparent conductive laminate according to claim 1,wherein the cross-linked polymer layer (A) has a surface facing thecross-linked polymer layer (B), said surface comprises micro bumpshaving an average height of 0.3 to 1 μm and a density of 350 to 1,800bumps/mm².
 3. The transparent conductive laminate according to claim 1,wherein the cross-linked polymer layer (B) is 20 to 110 nm in thickness.4. The transparent conductive laminate according to claim 1, wherein thecross-linked polymer layer (A) comprises a radiation-cured acrylicresin.
 5. The transparent conductive laminate according to claim 1,wherein the fine particles have an average diameter of 2 to 4 μm.
 6. Thetransparent conductive laminate according to claim 1, wherein thecross-linked polymer layer (B) does not contain fine particlessubstantially.
 7. The transparent conductive laminate according to claim1, wherein the cross-linked polymer layer (B) is obtained byhydrolyzation and condensation polymerization of a metal alkoxide. 8.The transparent conductive laminate according to claim 1, wherein thetransparent polymer substrate is a film or sheet of a thermoplasticpolymer.
 9. The transparent conductive laminate according to claim 1,wherein the transparent conductive layer comprises mainly a metal oxide.10. A transparent conductive laminate comprises a transparent polymersubstrate and a transparent conductive layer, said transparent polymersubstrate is a thermoplastic polymer film or sheet, said transparentconductive layer comprising mainly a metal oxide, wherein thetransparent conductive layer is disposed on one of sides, and thetransparent conductive layer has a surface containing micro bumps,further wherein: (1) said transparent conductive laminate comprises,between the transparent polymer substrate and the transparent conductivelayer, a radiation-cured resin layer (A1) which comprises an acrylicresin containing fine particles having an average diameter of 2 to 4 μm,and a cross-linked polymer layer (B1) which does not containing fineparticles substantially and obtained by hydrolyzation and condensationpolymerization of a metal alkoxide, said radiation-cured resin layer(A1) is disposed between said transparent polymer substrate and thecross-linked polymer layer (B1); (2) said cross-linked polymer layer(B1) has 20 to 110 nm in thickness and contacts with the transparentconductive layer; and (3) said transparent conductive layer has asurface containing midcro bumps having an average height of 0.3 to 1 μmand a density of 350 to 1,800 bumps/mm².
 11. The transparent conductivelaminate according to claim 1, the laminate further comprises across-linked polymer layer (C) disposed between the cross-linked polymerlayer (A) containing fine particles and the cross-linked polymer layer(B), said cross-linked polymer layer (C) has a higher refractive indexthan that of the cross-linked polymer layer (B).
 12. The transparentconductive laminate according to claim 11, wherein said transparentconductive layer has a surface having an average reflectance of not morethan 5.5% in wavelength of 450 to 650 nm and a b* value of transmittedlight being −2 to +3, wherein said b* value is obtained based onpsychometric chroma coordinates in the CIE 1976 (L*a*b*) Space accordingto Japan Industrial Standard No. Z8729.
 13. The transparent conductivelaminate according to claim 12, wherein the cross-linked polymer layer(C) has a refractive index in a range of 1.7 and +0.3 higher than therefractive index of said transparent conductive layer, and has 20 to 90nm in thickness; said cross-linked polymer layer (B) has 1.35 to 1.5 inrefractive index and 30 to 110 nm in thickness; said transparentconductive layer has 12 to 30 nm in thickness; and the cross-linkedpolymer layer (C), the cross-linked polymer layer (B) and thetransparent conductive layer have 180 to 230 nm in total of optical pathlength of each layer (wherein the optical path length is a valueobtained by multiplying a refractive index of a layer with a thicknessof the layer).
 14. The transparent conductive laminate according toclaim 13, wherein the cross-linked polymer layer (C) and thecross-linked polymer layer (B) are cross-linked polymer layers obtainedby mainly hydrolyzation and condensation polymerization of metalalkoxides, respectively.
 15. The transparent conductive laminateaccording to claim 12, wherein said cross-linked polymer layer (C) has arefractive index in a range of 1.7 and +0.3 higher than the refractiveindex of said transparent conductive layer; said cross-linked polymerlayer (B) has 1.35 to 1.5 in refractive index; said transparentconductive layer has 12 to 30 nm in thickness; and said polymer layer(B) has a minimum point of surface reflectance within a wavelength rangebetween 260 and 390 nm.
 16. The transparent conductive laminateaccording to claim 15, wherein said cross-linked polymer layer (C) andsaid cross-linked polymer layer (B) are cross-linked polymer layersobtained by mainly hydrolyzation and condensation polymerization ofmetal alkoxides, respectively.
 17. A touch panel comprising twotransparent electrode substrates, each of the substrates has aconductive layer at least one side of the substrate, the transparentconductive layers of the two substrates face each other, characterizedin that at least one of the transparent conductive substrates is thetransparent conductive laminate according to claim
 1. 18. The touchpanel according to claim 17, said touch panel further comprises atransparent polymer film or sheet being laminated to a side opposite tothe side where the transparent conductive layer of the transparentconductive laminate is formed.